Telomerization of Butadiene with C—H-Acidic Compounds

Compounds with methylene and methyne groups in the neighbourhood of two electronegative groups X and Y undergo telomerizations with butadiene very smoothly one or two acidic hydrogens can be replaced with the octa-2,7-dienyl group to produce the mono- and disubstituted compounds, respectively (Equation 14). 

In general, the methylene and methyne groups must be activated by two carbonyl groups. The carbonyl, formyl and carboxyl group form highly 

The telomer of malonate and butadiene is a particularly useful starting material. An example is given in Equation (15), which shows another synthesis of the naturally occuring pesticide pellitorine (compare Section 1.1) [15]. 

The same telomer was used by Baker et al. to synthesize the dimethyl-pentadecari 2-ol, the pheromone of the pine sawfly [16]. Also the queen substance, a well-known honey bee pheromone, is formed starting from the malonate telomer, which has exactly the right carbon number and a suitable functionality for a facile synthesis of this natural product (Equation 16) [17]. 

Zakharkin published the stereospecific synthesis oi 6E, llZ-hexadecadien-1-yl acetate, the Antheraca polyphemus pheromone, accomplished on the basis of either the malonate or the acetoacetate telomer [18]. The acetoacetate telomer is also the precursor of one of the royal jelly acids, the lO-hydroxy-2-decenoic acid (Equation 17) [19]. 

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